The present invention concerns a method in accord with tracked vehicles.
Generic travel systems of the type of this invention are mostly constructed as elevated railways. Elevated railways customarily possess columns which are spaced across from one another, between which are located beams which pick up the railway design loadings imposed on them. These beams reach longitudinally from column to column. The columns and the beams are subjected to both static and dynamic operational forces. On this account, they must be dimensioned to meet the magnitude of the imposed loads. The beams, in many cases, especially where magnetically levitated high speed vehicles are concerned, must also be fitted with functional components for said vehicles. These components, to carry out their function, can allow only a very small deviation of position. Consequently, in the construction of the beams, together with their functional appurtenances, it is very difficult to maintain the required close tolerances in an economical number of preparatory steps.
When such travel ways have been constructed for a relatively long operational life, because of shrinkage and creep processes, in both the foundations and in the structures thereon, it is very difficult to maintain or guarantee the relative small tolerances in the dimensioning of the travel way for its entire operating life.
EP 0 410 153 A1 discloses a beam construction for the travel way of a tracked vehicle. The necessary beams are, in accord with the embodiment, either made in steel or in concrete. Necessary appurtenances, in this disclosure, are affixed precisely in position on the beams. To this end, it is proposed in the application, that on the beam connection bodies first stop plates be attached. These first stop plates correspond with second stop plates, which are placed on transverse members carrying the appurtenances. After the units with the first stop plates are fastened to the beam, then these first stop plates are machined, so that the required tolerances for the installation of the appurtenances maintained. The machining of the stop plates may be advantageously carried out in an air conditioned fabrication facility under controlled climate conditions. The disadvantage of this procedure lies in the following. Although it is true that the machining of the stop plates is indeed possibly exact where the beams are concerned, after erection of the beams on the construction site, deviations may be expected. These deviations originate especially in the use of prefabricated concrete beams, pretensioned concrete beams, or even steel reinforced beams. These deviations can, for instance, arise from the deformation of the individual steel reinforced concrete beams during placement on the support columns. If, upon the erection of these steel reinforced beams, a vertical or horizontal offset arises, then the previously exactly machined stop plates are no longer within the allowed tolerances relative to the complete travel way. This problem was not recognized in the EP 0 410 153 A1.
Consequently, a purpose of the invention is to create a possibility of maintaining the required tolerances during the construction of a generic travel way, not only in relation to the beams, but also in relation to the complete travel way.
By the expression xe2x80x9cerected conditionxe2x80x9d,the condition of the beam, or another travel way component, is to be understood in accordance with a conventional erection of a travel way of a rail-bound vehicle. This means, the measurements of the beam, and/or of the travel way components at the time when the beam is installed and positioned on the support columns and after a state of equilibrium has been reached as to shrinkage and warping of the concrete beam and of the travel way components. The term, xe2x80x9creworked conditionxe2x80x9d indicates the state of the beam and the travel way components during machining of steel and/or concrete, when the state of equilibrium or the individual positioning of the reworked component during the said machining is not yet attained.
In accord with the invention, the beam is essentially shaped to correspond with its final structural position, or erected with a known deviation from its later dimensioning. The position of the connection points between the beam and the appurtenances is measured and, if required, conformation is made to prescribed dimensions of said connection points. This specified measure is carried out, so that at the connection point material may be removed or added. By the invention, the special advantage is achieved, in that the beam can be constructed in a fabrication hall to the most extreme precision, wherein the climatic conditions are of the best to obtain very small tolerances. These small tolerances, especially in the case of magnetically levitated travel ways, are very important in order that a trouble-free operation of the magnetically levitated equipment can be assured. In accord with this, it is not sufficient to merely hold to this exact dimensioning in the air-conditioned fabrication hall. Therefore the next step would naturally be to advantageously situate the beam in the same position that it will be positioned in the travel way in accord with predetermined measurements. Thus, during rework of the connection points, the beam is positioned in the same manner as in its final erected situation. Thus, the deformations such as might be expected on the construction site, for the individual beam, are still in force during the working of the connection points. In this way, the beam is provided with predetermined dimensioning for connection points, as will be required of the said beam in the final erection when the travel way is constructed.
Alterative, the deviation between the rework position of the beam and the later erected position can be determined by computer and taken into consideration when the connection points are machined. The connection points of the beam in such a case are reworked with a defined variance between the later specified dimensioning and the actual reworked dimensions. The deviation takes into consideration the different positioning as held during rework and the later erection of the beam. Then, when the beam is erected in its foreseen place, the measurements required in the field agree with the actual measurements of the beam; that is, with the connection points thereon. By means of the invented procedure, the most precise fabrication of the connection point for a travel wayxe2x80x94especially for magnetically levitated waysxe2x80x94is obtained. With the invented procedure, individual beams can be custom made, which are intended to be erected in a specific place in the travel way. This guarantees the greatest, degree of precision and thereby assures reliable operation, especially where magnetically levitated vehicles are concerned.
In accord with a further invented procedure following in another embodiment, an exact positional dimensioning can be made between connection points for the fastening of appurtenances or between functional surfaces on the beam for the vehicle. In this case, a specified dimension for the erected condition of the beam is predetermined. If the erected condition of the beam is seen to deviate from the said specified dimension, then a second specified dimensioning is determined for the rework condition. The specified dimensioning of the connection points or the functional surfaces in the machining condition of the beam is determined, and as may be demanded, the required first or second specified dimension becomes the basis for the rework condition of the beam. In this way material at the connection point or on the function surfaces is removed or replenished. The rework of the connection point can be either on the beam itself or on a console between the beam and the functional surfaces, or on an added appurtenance which bears the said functional surface, or indeed, on the appurtenance itself. The same is valid for the procedure in accord with the embodiment above. Where the case concerns the fact that the erection condition and the rework condition are identical, then the first and the second predetermined dimensioning must be identical. Thus the rework then can be carried out in such a manner that the predetermined measurement as it should appear in the erected condition of the beam is achieved by the rework.
Since, for the operation of the vehicle it is especially important that the functional surfaces be exactly positioned, at this point it can be particularly advantageous if the functional surfaces themselves are subjected to measurement and the rework operation carried out accordingly and in keeping with these functional surfaces. In this way, fine tolerances can be eliminated, which must be held between the connection point and for example an appurtenance, which carries the functional surface. Thus an optimal condition for the functional surfaces is obtained within the travel way.
It is of particular advantage if the beam when positioned for rework, is in correspondence with its later erected position. To this end, a computation between the predetermined value of the erected position and the predetermined value in the machining condition can be omitted, since these two dimensioning are identical.
Customarily, the measurements to be achieved by machining, concern: the outside dimension between two oppositely disposed connection points or functional surfaces, an angle, and a separating distance of a connection point to a previous or following connection point as seen in the in the longitudinal direction of the travel way.
These dimensions customarily characterize the exact guidance of the vehicle, so that these dimensions underlay the machining, in order to obtain an exact guidance of the vehicle.
In order to maintain an exact specified dimension it is an advantage if reference points, that is lines or planes or a centerline of the beam is determined, from which reference means the specified measurement can be laid down. In this way, appurtenances or the functional surfaces are correct, but the position is now referred to the beam. This way, an offset could occur which would prevent the exact guidance of the vehicle.
If the beam is a precast concrete part, then it is especially an advantage if before the rework of the beam, or the machining of the connection points on the beam, the precast concrete beam be initially stored until any shrinkage has ceased. By this means what is achieved is that by a change in the beam the reworked specified dimensioning must also change. If the shrinkage of the beam is predominately at an equilibrium state, then when the rework is carried out, a change in the dimensioning of the beam is no longer to be feared and the specified measurements can accordingly be maintained. If the beam is let lie for some 60 days before the rework is done, the shrinkage of the beam is essentially over and the rework can be carried out with exact results.
If the appurtenances following the rework of the connection points but prior to the erection of the beam are placed in the travel way then once again a dimensional monitoring of the appurtenances can take place, especially of the functional surfaces. Assurance may be made that the functional surfaces are placed on the beam in a precise manner. If necessary, the functional surfaces can be reworked.
It is particularly advantageous if the appurtenances are measured magnetically. In this way, especially in the case of magnetically levitated travel ways, measurements are made of a stator packet to determine its magnetic field. The magnetic field is the criterion for exact guidance of the vehicle of a magnetically levitated travel way so that by means of the magnetic measurement a particularly precise guidance of the vehicle is made possible. The specified measurement, in the respect, directs itself in accord with the actual magnetic field of the travel way.
If the material at the connection point between the beam and the appurtenance is removed or built up sequentially when the required measurement has been reached, the appurtenance is mounted. For this mounting, a secure and stable connection point is created, which is dimensionally correct with even the small tolerances necessary for the safe operation of the magnetically levitated travel system. One particular advantage of the invention is that the connection point at the construction site has the proper dimensions.
It is favorable if the measurement or the rework of the connection point is carried out by means of a tracked vehicle. The tracked vehicle is guided along the beam and by this method effects an exact dimensioning and rework of the connection position.
It is of particular advantage if the connection point is provided with a console connected to the beam. The console, in this service, can be advantageously shaped, so that it is particularly well adapted to the measurement of the connection position and the rework of the same. Also, the material selection of the console is independent of the properties which the beam must fulfill. Thus the said material must be so chosen that the rework and the connection with the appurtenance is optimal.
By means of a particular formulation of the console, the connection point can be mechanically reworked on the console either before or after it is mounted on the beam. This allows for example a first pre-machining, and a subsequent mounting of the console on the beam and if necessary a second machining of the connection point.
Normally, the material is removed by machine cutting, that is by milling or boring to dimension the corresponding connection points. However, the rework of the connection point can be done by means of a laser or other metal working methods.
If required by the selection of appropriate materials of the console, the connection point material can be welded when connected to the beam. By this means, a deficiency in the dimensioning can be compensated for.
In case of such a deficiency in dimensioning, also an additional object can be inserted in the role of a spacer. Adaptable to this service would be a thin section or a shim plate. This additional material can, for instance by welded onto the connection point and subsequently be again cut back, if necessary, to the specified dimensioning.
If the measurement and the rework is carried out after the end of the deformation procedure, i.e., that deformation due to creep and shrinkage, then a long lasting retention of the correct specified dimensioning will be achieved and the tolerances reliably maintained since the material will no longer be subject to dimensional change. Further, this a special advantage of the present invention since in accord with the state of the technology, further deformations are to be contended with where rework of the corresponding connection points is carried out immediately after fabrication in a plant, especially in the case of concrete work. These changes come to an essential equilibrium only after several weeks, so that the normal period between the fabrication and the time of erection of the beam is advantageous since upon the erection of the beam these internal deformations are predominately ended.
The measurement of the connection position is carried out essentially from reference points, reference lines or guide planes. This assures that the required measurements are correctly maintained. A tracked measurement/rework vehicle orients itself on the reference points, reference lines or guide planes, in accord with one concept of the invention in order to carry out measurements.
Following the above, the connection of the consoles with the beams is accomplished, and the carrying-elements are attached to the consoles after the full cure and associated shrinkage of the concrete has taken place. In this way, the positional changes brought about by the deformation of the concrete can be avoided.
The invention offers because of its modular construction the additional advantage, that the consoles and the carrying elements can be mechanically reworked before as well as after their mounting. Even extreme tolerance requirements permit themselves to be easily fulfilled hereby in all space axes. The modular construction makes possible, besides more exact and economical fabrication, a simple replacement for accidentally damaged carrying elements for the functional pieces.
Finally, the space curve for the functional plane can be well brought about by appropriate formation and/or rework of the console abutments.
In order to even out large positional changes, different consoles can be provided, which possess webs of different lengths. In this way, in the case of a large offset of the beam on its specified position, an oversized console can be can be installed which finally fastens the appurtenance in its desired position.
In order to acquire a high degree of stability in the fastening of the console on the beam, it is particularly of advantage if the beam is made of fiber reinforced concrete. Fiber reinforced concrete acts in the present case so that even in flange areas of the beam to which the console is attached a substantial structural strength of the concrete is obtained However, the console must not compromise the conventional structural properties of the beam, in order to obtain a good stability.
Further advantages and embodiments of the invention are described in the following.